Users of social network applications increasingly use these applications not just to chat, but also to share lots of images, photos, music and videos. Users share their episodes of lives, hobbies, feelings, thoughts, gossips, experiences, by using increasingly rich multi-media methods. While current social network applications often provide functions of document sharing, the focus of the sharing is on each single document. Users have to manually collect each document related to one theme and share them one by one. For users, these documents are stored and shared out of context. This traditional document-oriented approach is based on how computer handles documents. Yet this approach often frustrates social interactions, which are typically theme oriented or topic oriented. Therefore, it is desirable to have a method that enables users to store and share documents based on the topics and themes.